The detection of clusters comprising magnetic particles by rotating them and detecting the light scattered in a dark field configuration is known from literature (Ranzoni, A., Schleipen, J. J. H. B., van Ijzendoorn, L. J. & Prins, M. W., “Frequency-Selective Rotation of Two-Particle Nanoactuators for Rapid and Sensitive Detection of Biomolecules”, Nano Lett 11, 2017-2022). In the described setup, a sample with the clusters is provided in a cuvette.